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Colorectal cancer is a major cause of cancer mortality and is considered to be largely attributable to inappropriate lifestyle and behavior patterns. The purpose of this review was to undertake a comparison of the strength of the associations between known and putative risk factors for colorectal cancer by conducting 10 independent meta-analyses of prospective cohort studies. Studies published between 1966 and January 2008 were identified through EMBASE and MEDLINE, using a combined text word and MESH heading search strategy. Studies were eligible if they reported estimates of the relative risk for colorectal cancer with any of the following: alcohol, smoking, diabetes, physical activity, meat, fish, poultry, fruits and vegetables. Studies were excluded if the estimates were not adjusted at least for age. Overall, data from 103 cohort studies were included. The risk of colorectal cancer was significantly associated with alcohol: individuals consuming the most alcohol had 60% greater risk of colorectal cancer compared with non-or light drinkers (relative risk 1.56, 95% CI 1.42-1.70). Smoking, diabetes, obesity and high meat intakes were each associated with a significant 20% increased risk of colorectal cancer (compared with individuals in the lowest categories for each) with little evidence of between-study heterogeneity or publication bias. Physical activity was protective against colorectal cancer. Public-health strategies that promote modest alcohol consumption, smoking cessation, weight loss, increased physical activity and moderate consumption of red and processed meat are likely to have significant benefits at the population level for reducing the incidence of colorectal cancer. ' UICCKey words: meta-analysis; colorectal cancer; lifestyle; smoking; alcohol Cancers of the colon and rectum (colorectal) constitute a significant proportion of the global burden of cancer morbidity and mortality, particularly in developed countries where these malignancies rank second in terms of both incidence and mortality, compared with fifth in less developed countries. 1 Annually, approximately 1 million new cases of colorectal cancer are diagnosed, and more than half a million people die from colorectal cancer, equivalent to approximately 8% of all cancer-related deaths worldwide. The occurrence of colorectal cancer varies at least 25-fold between countries 1,2 with the highest incidence rates for colorectal cancer seen in certain areas and ethnic groups in the United States, Canada, Japan and New Zealand.3 The wide geographical variation in incidence rates for colorectal cancer, and data from migrant studies, 4 suggest that lifestyle risk factors, including diet, 5,6 physical activity, 7 obesity 8 and diabetes, 9 play a pivotal role in the aetiology of the disease. 10 A high consumption of different processed foods and alcohol intakes have also been associated with a higher colorectal cancer risk. 11 The proportion of colorectal cancer attributed to dietary factors has been estimated to be about 50%.12 Further, approxim...

OBJECTIVEWe evaluated whether a whey preload could slow gastric emptying, stimulate incretin hormones, and attenuate postprandial glycemia in type 2 diabetes.RESEARCH DESIGN AND METHODSEight type 2 diabetic patients ingested 350 ml beef soup 30 min before a potato meal; 55 g whey was added to either the soup (whey preload) or potato (whey in meal) or no whey was given.RESULTSGastric emptying was slowest after the whey preload (P < 0.0005). The incremental area under the blood glucose curve was less after the whey preload and whey in meal than after no whey (P < 0.005). Plasma glucose-dependent insulinotropic polypeptide, insulin, and cholecystokinin concentrations were higher on both whey days than after no whey, whereas glucagon-like peptide 1 was greatest after the whey preload (P < 0.05).CONCLUSIONSWhey protein consumed before a carbohydrate meal can stimulate insulin and incretin hormone secretion and slow gastric emptying, leading to marked reduction in postprandial glycemia in type 2 diabetes.

Background: It is currently unclear whether altering the carbohydrateto-protein ratio of low-fat, energy-restricted diets augments weight loss and cardiometabolic risk markers. Objective: The objective was to conduct a systematic review and meta-analysis of studies that compared energy-restricted, isocaloric, high-protein, low-fat (HP) diets with standard-protein, low-fat (SP) diets on weight loss, body composition, resting energy expenditure (REE), satiety and appetite, and cardiometabolic risk factors. Design: Systematic searches were conducted by using MEDLINE, EMBASE, PubMed, and the Cochrane Central Register of Controlled Trials to identify weight-loss trials that compared isocalorically prescribed diets matched for fat intake but that differed in protein and carbohydrate intakes in participants aged $18 y. Twenty-four trials that included 1063 individuals satisfied the inclusion criteria.

Fatty acids are the chemical moieties that are thought to stimulate oral nutrient sensors, which detect the fat content of foods. In animals, oral hypersensitivity to fatty acids is associated with decreased fat intake and body weight. The aims of the present study were to investigate oral fatty acid sensitivity, food selection and BMI in human subjects. The study included two parts; study 1 established in thirty-one subjects (29 (SEM 1·4) years, 22·8 (SEM 0·5) kg/m 2 ) taste thresholds using 3-AFC (3-Alternate Forced Choice Methodology) for oleic, linoleic and lauric acids, and quantified oral lipase activity. During study 2, fifty-four subjects (20 (SEM 0·3) years, 21·5 (SEM 0·4) kg/m 2 ) were screened for oral fatty acid sensitivity using oleic acid (1·4 mM), and they were defined as hypo-or hypersensitive via triplicate triangle tests. Habitual energy and macronutrient intakes were quantified from 2 d diet records, and BMI was calculated from height and weight. Subjects also completed a fat ranking task using custard containing varying amounts (0, 2, 6 and 10 %) of fat. Study 1 reported median lipase activity as 2 mmol fatty acids/ min per l, and detection thresholds for oleic, linoleic and lauric acids were 2·2 (SEM 0·1), 1·5 (SEM 0·1) and 2·6 (SEM 0·3) mM. Study 2 identified twelve hypersensitive subjects, and hypersensitivity was associated with lower energy and fat intakes, lower BMI (P,0·05) and an increased ability to rank custards based on fat content (P,0·05). Sensitivity to oleic acid was correlated to performance in the fat ranking task (r 0·4, P,0·05). These data suggest that oral fatty acid hypersensitivity is associated with lower energy and fat intakes and BMI, and it may serve as a factor that influences fat consumption in human subjects.

Overweight women with polycystic ovary syndrome (PCOS) were randomized to a high protein (HP; 40% carbohydrate and 30% protein; n = 14) or a low protein (LP; 55% carbohydrate and 15% protein) diet (n = 14). The intervention consisted of 12 wk of energy restriction (approximately 6000 kJ/d), followed by 4 wk of weight maintenance. Pregnancies (two HP and one LP); improvements in menstrual cyclicity, lipid profile, and insulin resistance (as measured by the homeostasis model); and decreases in weight (7.5%) and abdominal fat (12.5%) occurred independently of diet composition. Improvements in menstrual cyclicity were associated with greater decreases in insulin resistance and fasting insulin (P = 0.011). On the LP diet, high density lipoprotein cholesterol decreased 10% during energy restriction (P = 0.008), and the free androgen index increased 44% in weight maintenance stages (P = 0.027). Weight loss leads to improvements in cardiovascular and reproductive parameters potentially mediated by improvements in surrogate measures of insulin resistance. An HP weight loss diet may result in minor differential endocrine and metabolic improvements.

OBJECTIVE -To determine the effect of a high-protein (HP) weight loss diet compared with a lower-protein (LP) diet on fat and lean tissue and fasting and postprandial glucose and insulin concentrations.RESEARCH DESIGN AND METHODS -Replacing dietary protein for carbohydrate (CHO) during energy restriction and weight loss has been effective in sparing lean mass and improving insulin sensitivity in obese subjects but has not been tested in subjects with type 2 diabetes. We compared an HP diet (28% protein, 42% CHO, 28% fat [8% saturated fatty acids, 12% monounsaturated fatty acids, 5% polyunsaturated fatty acids]) with an LP diet (16% protein, 55% CHO, 26% fat [8% saturated fatty acids, 11% monounsaturated fatty acids, 5% polyunsaturated fatty acids]) in 54 obese men and women with type 2 diabetes during 8 weeks of energy restriction (1,600 kcal) and 4 weeks of energy balance. Body composition was determined by dual-energy X-ray absorptiometry at weeks 0 and 12.RESULTS -Overall, weight loss of 5.2 Ϯ 1.8 kg was achieved independently of diet composition. However, women on the HP diet lost significantly more total (5.3 vs. 2.8 kg, P ϭ 0.009) and abdominal (1.3 vs. 0.7 kg, P ϭ 0.006) fat compared with the women on the LP diet, whereas, in men, there was no difference in fat loss between diets (3.9 vs. 5.1 kg). Total lean mass decreased in all subjects independently of diet composition. LDL cholesterol reduction was significantly greater on the HP diet (5.7%) than on the LP diet (2.7%) (P Ͻ 0.01).CONCLUSIONS -Both dietary patterns resulted in improvements in the cardiovascular disease (CVD) risk profile as a consequence of weight loss. However, the greater reductions in total and abdominal fat mass in women and greater LDL cholesterol reduction observed in both sexes on the HP diet suggest that it is a valid diet choice for reducing CVD risk in type 2 diabetes. Diabetes Care 25:425-430, 2002T ype 2 diabetes is a major public health problem in the developed world (1). Although there is a strong genetic predisposition to the development of type 2 diabetes, lifestyle and dietary factors, particularly those that promote obesity, are contributors (2). Type 2 diabetes is characterized in most subjects by insulin resistance with inadequate insulin response to maintain normoglycemia (3). Insulin resistance occurs partly as a result of increased concentrations of circulating plasma free fatty acids, released from excess adipocytes in obesity, which compete with glucose for uptake in skeletal muscle (4). In addition, hormones such as resistin (5) and cytokines such as tumor necrosis factor-␣ (6) released from adipocytes may exacerbate insulin resistance. Because ϳ90% of people with type 2 diabetes are obese, weight loss is essential in management. The optimal diet for type 2 diabetes has been the focus of much research, and there remains no consensus on macronutrient composition apart from recommendations that saturated fats be kept low (7). Energy restriction alone significantly improves glucose control and the plasma lipid pro...

Acute appetite and energy intake are equally reduced after consumption of lactose, casein, or whey compared with glucose, which was consistent with differences in plasma ghrelin. Higher CCK responses after proteins correlated with satiety but did not affect energy intake.